Modern electronic systems are often implemented using removable modules containing electronic components. These electronic modules, or LRUs, include printed wire/circuit boards (PWBs/PCBs) or “circuit cards”, and provide quick replacement or repair, simplified system packaging and reduced cost. In some applications, these modules comprise high-power electronic components which generate large amounts of heat during operation. In order to prevent damage and extend the service life of these components, separate conductive cooling systems are often implemented into these systems. These cooling systems may comprise, for example, heat sinks or heat exchangers embodied as heat-conducting chasses or frames which may be air or liquid-cooled, or may simply comprise a large thermal capacity.
In traditional systems, LRUs are generally “edge-cooled”, or held on their ends within slots formed on opposing “cold walls” or “cold plates” of a chassis. For example, FIG. 1 partially illustrates a cooling and retaining system 2 using traditional expanding card retainers in an edge-cooled configuration. The system includes a cooling chassis or cold wall 15 having a plurality of elevated wall sections 16 formed therein defining a plurality of slots. Edge-cooled units (e.g. LRUs) 17 are typically inserted into these cold wall slots, and clamped in place along their opposing edges via expanding “wedge locks” or “card retainers” 18. Such edge-cooled arrangements with card retainers suffer from several significant drawbacks. For example, cooling is relatively inefficient, as contact with the cold walls occurs only at the edges of the units. Moreover, the card retainers do not allow for easy extraction of the units, or the retainers themselves, because they often do not fully contract back to their non-expanded height, even when properly unlocked.
Alternative systems and methods are for LRU retention and cooling are desired.